Signal encoding and decoding method, device and system

1. A wireless signal encoding and decoding method, comprising the following steps: encoding, at a transmit end, a first binary bit value in data into a level that lasts for a first duration, and encoding a second binary bit value in the data into a level that lasts for a second duration, levels are separated by delimiters, and the first duration is unequal to the second duration; converting encoded data levels into a wireless optical signal at the transmit end; receiving the wireless optical signal at a receive end, and converting the wireless optical signal into an electric signal; decoding the electric signal at the receive end in the following manner: recording a duration of each level of the electric signal; calculating a first average value Ta of m maximum durations and a second average value Tb of n minimum durations, the m and n are positive integers and are determined by referring to a distribution percentage value of first binary bit values and a distribution percentage value of second binary bit values in the data respectively; calculating a decision duration Td according to the first average value and the second average value; comparing the duration of each level with the decision duration, and according to a comparison result, determining a binary bit value represented by the level; and integrating all binary bit values to restore the data.

2. The method according to claim 1 , wherein the level that lasts for the first duration and the level that lasts for the second duration are characteristic levels, and delimiters between reference levels are reference levels different from the characteristic levels.

3. The method according to claim 1 , wherein the delimiters between the levels are level jumps.

4. The method according to claim 2 , further comprising: interchanging the first binary bit value and the second binary bit value if a quantity of the first binary bit values is greater than a quantity of the second binary bit values in the data when the first duration is greater than the second duration; or, interchanging the first binary bit value and the second binary bit value if a quantity of the second binary bit values is greater than a quantity of the first binary bit values in the data when the second duration is greater than the first duration.

5. The method according to claim 2 , further comprising: interchanging the first binary bit value and the second binary bit value in a segment of the data if a quantity of the first binary bit values is greater than a quantity of the second binary bit values in the segment of the data when the first duration is greater than the second duration; or, interchanging the first binary bit value and the second binary bit value in a segment of the data if a quantity of the second binary bit values is greater than a quantity of the first binary bit values in the segment of data when the second duration is greater than the first duration.

6. The method according to claim 1 , wherein the distribution percentage value of the first binary bit values and the distribution percentage value of the second binary bit values in the data are predetermined, m is less than or equal to a product of a total quantity of the levels and the distribution percentage value of the first binary bit values, and n is less than or equal to a product of the total quantity of the levels and the distribution percentage value of the second binary bit values.

7. The method according to claim 1 , wherein the distribution percentage value of the first binary bit values and the distribution percentage value of the second binary bit values in the data are random.

8. The method according to claim 7 , wherein m is less than or equal to P/3, and n is less than or equal to P/3, P is a total quantity of levels in the signal, and both m and n are greater than or equal to 3.

9. The method according to claim 1 , wherein the step of determining, according to a comparison result, a binary bit value represented by the level comprises: when the first duration is less than the second duration, if a duration of a level is less than or equal to the decision duration, the level represents the first binary bit value, or, if a duration of a level is greater than the decision duration, the level represents the second binary bit value; and when the first duration is greater than the second duration, if a duration of a level is less than or equal to the decision duration, the level represents the second binary bit value, or, if a duration of a level is greater than the decision duration, the level represents the first binary bit value.

10. The method according to claim 1 , wherein the wireless optical signal comprises at least one of an infrared optical signal, a visible light signal, and an ultraviolet light signal.

11. The method according to claim 1 , wherein a relationship between the decision duration Td and the first average value Ta and the second average value Tb is: Td=(Ta+Tb)/2.

12. A wireless signal decoding method, which is used to decode an electric signal converted from a wireless optical signal, wherein the decoding method comprises the following steps: receiving, by an electronic device, a wireless optical signal and converting the wireless optical signal into the electric signal; detecting, by the electronic device, the electric signal, and recording a duration of each level of the electric signal; calculating, by the electronic device, a first average value Ta of m maximum durations and a second average value Tb of n minimum durations, the m and n are positive integers and are determined by referring to a distribution percentage value of first binary bit values and a distribution percentage value of second binary bit values in the data respectively; calculating, by the electronic device, a decision duration Td according to the first average value and the second average value; comparing, by the electronic device, the duration of each level with the decision duration, and according to a comparison result, determining a binary bit value represented by the level; and integrating, by the electronic device, all binary bit values to restore the data represented by the electric signal.

13. The method according to claim 12 , wherein the distribution percentage value of the first binary bit values and the distribution percentage value of the second binary bit values in the data are predetermined, m is less than or equal to a product of a total quantity of the levels and the distribution percentage value of the first binary bit values, and n is less than or equal to a product of the total quantity of the levels and the distribution percentage value of the second binary bit values.

14. The method according to claim 12 , wherein the distribution percentage value of the first binary bit values and the distribution percentage value of the second binary bit values in the data are random.

15. The method according to claim 14 , wherein m is less than or equal to P/3, and/or n is less than or equal to P/3, P is a total quantity of levels in the electric signal, and both m and n are greater than or equal to 3.

16. The method according to claim 12 , wherein the step of determining, by the electronic device, according to a comparison result, a binary bit value represented by the level comprises: when the first duration is less than the second duration, if a duration of a level is less than or equal to the decision duration, the level represents the first binary bit value, or, if a duration of a level is greater than the decision duration, the level represents the second binary bit value; and when the first duration is greater than the second duration, if a duration of a level is less than or equal to the decision duration, the level represents the second binary bit value, or, if a duration of a level is greater than the decision duration, the level represents the first binary bit value.

17. The method according to claim 15 , wherein a relationship between the decision duration Td and the first average value Ta and the second average value Tb is: Td=(Ta+Tb)/2.